Truncating mutations in C-terminal titin may cause more severe tibial muscular dystrophy (TMD).
Mutations in C-terminal titin cause autosomal dominant tibial muscular dystrophy (TMD) as reported previously. Samples from 25 new families and 25 sporadic new distal myopathy cases were screened for titin mutations. Three novel mutations were discovered in two families from Spain and two families from France. Two mutations, g.292998delT and g.293376delA lead to frameshift and premature stop codons in the second last and the last titin gene (TTN) exons, Mex5 and Mex6, respectively. The third was a nonsense mutation g.293379C>T (p.Q33396X) in Mex6. Patients with the upstream Mex5 mutation showed a more severe phenotype with earlier onset implying a genotype-phenotype correlation.
Hackman
Peter
P
Folkhälsan Institute of Genetics, Department of Medical Genetics, University of Helsinki, Haartmaninkatu 8, Pb 63, 00014 Helsinki, Finland. peter.hackman@helsinki.fi
Marchand
Sylvie
S
Sarparanta
Jaakko
J
Vihola
Anna
A
Pénisson-Besnier
Isabelle
I
Eymard
Bruno
B
Pardal-Fernández
Jose Manuel
JM
Hammouda
El-Hadi
el-H
Richard
Isabelle
I
Illa
Isabel
I
Udd
Bjarne
B
D000328:Adult; D000368:Aged; D001483:Base Sequence; D015153:Blotting, Western; D018389:Codon, Nonsense; D064211:Connectin; D004252:DNA Mutational Analysis; D049310:Distal Myopathies / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D005260:Female; D016368:Frameshift Mutation; D020022:Genetic Predisposition to Disease; D005838:Genotype; D006801:Humans; D008297:Male; D008875:Middle Aged; D008969:Molecular Sequence Data; D009124:Muscle Proteins / Q000235:genetics* / Q000378:metabolism; D018482:Muscle, Skeletal / Q000378:metabolism / Q000473:pathology; D009154:Mutation; D010375:Pedigree; D010641:Phenotype; D011494:Protein Kinases / Q000235:genetics* / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012720:Severity of Illness Index; D015898:Tomography Scanners, X-Ray Computed
D018389:Codon, Nonsense; D064211:Connectin; D009124:Muscle Proteins; C577285:TTN protein, human; D011494:Protein Kinases